Skip to main content
Join the official Python Developers Survey 2018 and win valuable prizes: Start the survey!

Background thread support with ZODB support

Project description

A library for creating background threads that can talk to the ZODB and use local site components.

We’re probably reinventing Celery.


Let’s assume we have a DMS with a simple publication workflow. We have two states “DRAFT” and “PUBLISH”. The Problem in this example is: that the transition form “DRAFT” to “PUBLISH” takes some minutes, and we don’t want the user to be waiting.

First we have create a WorkflowTransition-BackgroundThread:

class MyWorkflowTransition(BackgroundWorkerThread):
    execute = True
    description = "background worker thread (%(class_name)s) for %(site_name)s User %(user_name)s"

    def __init__(self, site_db, site_oid, site_name, user_name, daemon=True, object_oid=None):
        self.object_oid = object_oid
        super(MyWorker, self).__init__(site_db, site_oid, site_name, user_name, daemon=True)

    def scheduleNextWork(self):
        return self.execute

    def getObjectFromOID(self):
        conn = getSite()._p_jar
        return conn.get(self.object_oid)

    def doWork(self):
        sleep(15) # This is our long TASK
        self.execute = False
        document = self.getObjectFromOID()
        document.wf_status = "PUBLISHED"

We have a simple Document with an initial Workflow-State draft.

class Document(Persistent):
    wf_state = "DRAFT"

Now we have to call our WorkflowTransition.

def setWorkflow(site, document_oid, user_name):
    worker = MyWorkflowTransition(
        site_db = site._p_jar.db(),
        site_oid = site._p_oid,
        site_name = site.__name__,
        user_name = user_name,
        object_oid = document_oid,

When calling worker.start() the thread goes into “Background” and the user don’t have to wait until the Transition is finished.


1.0.2 (2012-07-31)

  • Refactor BackgroundWorkerThread to have the site returned from getSite()

1.0.1 (2012-04-05)

1.0.0 (2012-02-10)

  • Initial release as a separate package.

Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Filename, size & hash SHA256 hash help File type Python version Upload date
cipher.background-1.0.2.tar.gz (14.6 kB) Copy SHA256 hash SHA256 Source None Aug 2, 2012

Supported by

Elastic Elastic Search Pingdom Pingdom Monitoring Google Google BigQuery Sentry Sentry Error logging AWS AWS Cloud computing DataDog DataDog Monitoring Fastly Fastly CDN SignalFx SignalFx Supporter DigiCert DigiCert EV certificate StatusPage StatusPage Status page